[compiler-rt] Allow c++ abi to be explictly disabled in cmake configuration

[fjricci]

Summary

This will allow for the sanitizers to be used when c++ abi is unavailable.

[fjricci]

Friendly ping. This patch will allow at least address sanitizer to be compiled and run without requiring c++ abi, which currently isn't possible.

[rnk]

CMakeLists.txt

217

I think you should hoist this up to the end of the options and make this an option(). Use the existing logic to provide the default value.

[fjricci]

Use option instead of define

[rnk]

Almost, sorry I wasn't clear

CMakeLists.txt

95

I'd rather not duplicate option() with its text description. You can get the same effect with set(use_cxxabi_default ON/OFF) and feeding that into option()

[fjricci]

Refactor option parsing

[rnk]

lgtm, thanks

[fjricci]

This somehow caused a clang buildbot failure. Reverted and investigating.

[fjricci]

Fixed typo and re-committed as r278772

[fjricci]

Still one failing buildbot, which I can't seem to repro locally. I'll revert and come up with a new patch once I figure out what's going on.

[fjricci]

Looks like this is a problem with bad cmake caches on incremental builds (the typo in the original patch caused a bad default value to be inserted in the CMakeCache.txt, and default values don't get over-written unless you do a clean build). I'll re-commit next week when the incremental builds have all been reset.

CMakeLists.txt

 
 #================================
 # Setup Compiler Flags
 #================================
 
 include(config-ix)
 
 if(MSVC)
   # Override any existing /W flags with /W4. This is what LLVM does.  Failing to
   # remove other /W[0-4] flags will result in a warning about overriding a
   # previous flag.
   if (COMPILER_RT_HAS_W4_FLAG)
     string(REGEX REPLACE " /W[0-4]" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
     string(REGEX REPLACE " /W[0-4]" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
     append_string_if(COMPILER_RT_HAS_W4_FLAG /W4 CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
   endif()
 else()

 append_list_if(COMPILER_RT_HAS_WD4291_FLAG /wd4291 SANITIZER_COMMON_CFLAGS)
 append_list_if(COMPILER_RT_HAS_WD4391_FLAG /wd4391 SANITIZER_COMMON_CFLAGS)
 append_list_if(COMPILER_RT_HAS_WD4722_FLAG /wd4722 SANITIZER_COMMON_CFLAGS)
 append_list_if(COMPILER_RT_HAS_WD4800_FLAG /wd4800 SANITIZER_COMMON_CFLAGS)
 
 # Warnings to turn off for all libraries, not just sanitizers.
 append_string_if(COMPILER_RT_HAS_WUNUSED_PARAMETER_FLAG -Wno-unused-parameter CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 
+if (NOT DEFINED SANITIZER_CAN_USE_CXXABI)
   if(APPLE AND SANITIZER_MIN_OSX_VERSION VERSION_LESS "10.9")
     # Mac OS X prior to 10.9 had problems with exporting symbols from
     # libc++/libc++abi.
     set(SANITIZER_CAN_USE_CXXABI FALSE)
   elseif(MSVC)
     set(SANITIZER_CAN_USE_CXXABI FALSE)
   else()
     set(SANITIZER_CAN_USE_CXXABI TRUE)
   endif()
+endif()
 pythonize_bool(SANITIZER_CAN_USE_CXXABI)
 
 add_subdirectory(include)
 
 set(COMPILER_RT_LIBCXX_PATH ${LLVM_MAIN_SRC_DIR}/projects/libcxx)
 if(EXISTS ${COMPILER_RT_LIBCXX_PATH}/)
   set(COMPILER_RT_HAS_LIBCXX_SOURCES TRUE)
 else()

lib/ubsan/ubsan_type_hash_itanium.cc

 //===-- ubsan_type_hash_itanium.cc ----------------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // Implementation of type hashing/lookup for Itanium C++ ABI.
 //
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_common/sanitizer_platform.h"
 #include "ubsan_platform.h"
-#if CAN_SANITIZE_UB && !SANITIZER_WINDOWS
+#if CAN_SANITIZE_UB && UBSAN_CAN_USE_CXXABI
 #include "ubsan_type_hash.h"
 
 #include "sanitizer_common/sanitizer_common.h"
 
 // The following are intended to be binary compatible with the definitions
 // given in the Itanium ABI. We make no attempt to be ODR-compatible with
 // those definitions, since existing ABI implementations aren't.